Re: [PATCH v2] ld.so: Handle read-only dynamic section gracefully [BZ #28340]

[Florian Weimer via Libc-alpha <libc-alpha@sourceware.org>]

* Siddhesh Poyarekar:

> @@ -1149,6 +1152,9 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,
>  		 such a segment to avoid a crash later.  */
>  	      l->l_ld = (void *) ph->p_vaddr;
>  	      l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
> +#ifndef DL_RO_DYN_SECTION
> +	      readonly_dynamic = (ph->p_flags & PF_W) == 0;
> +#endif
>  	    }
>  	  break;

As far as I can tell, this does not check whether the DYNAMIC segment is
actually covered by a read-write LOAD segment.  I wonder how much value
this imperfect check has.

Would it make more sense to fix the kernel linker script that generates
those bogus vDSO reference files?

Thanks,
Florian